#define HEAD 0xFFFF
#define MAXBUFF 128
#define CRC_INIT 0xFFFF
#define CRC(crcval,newchar) crcval = (crcval >> 8) ^ \
        crc_table[(crcval ^ newchar) & 0x00ff]

int i,j;                                   // Counter
int inByte;                                // integer for first 8-bit packet's data
int inByte2;                               // integer for first 8-bit packet's data
word result;                               // word to control 16-bit packet's data    
int inBytesArr[MAXBUFF];                   // Container of packet's data
int oldTimeStamp = 0;                      // int for the timestamp control 
int timeStamp;                             // int for the timestamp control
int lung = 0;                              // To know the real length of the packet's container
int typepacket = 0;                        // To know the packet's type, 32-16-8 bit packet
int type1packet = 0;                       // To know the packet's type, ...3 CINPUT
char* verificaCRC[MAXBUFF];                // String to calculate the CRC16 
word polynom = 0xA001;                     // Generator Polynom for CRC16

//Program
void setup()
{
  Serial.begin(57600);
  Serial2.begin(38400);
  delay(100);
}

void loop() 
{
  if(Serial2.available() > 0)
  {
    Read();
  }
}

void Read() 
{ 
  ReadData();
  if(controlHeader0(inByte,inByte2) == true)		// Control that I'm reading packet's header(packet start)
  {
    ReadData();
    if(controlHeader1(inByte,inByte2))	                // Control the second part of header and assign the type
    {
      if(typepacket == 2)
      {
        i=2;
        ReadPacket();
        int lung = inBytesArr[0];
        /*
        if(ControlLenght() == false) 
        {
          Serial.println("Lunghezza Errata!");          //Lenght Control
        }
        */
        type1packet = inBytesArr[1];
        
        for(j=0;j<i;j++)
        {
          Serial.print(inBytesArr[j],HEX);
        }
        
        /*
        if(controltime == false || controlSum == false)
        {
          Serial.println("CRC16 Errato!");              // CRC16 Control
        } 
        
        if(controltime == false || controlSum == false)
        {
          Serial.println("Tempo o Dati all'interno del pacchetto Errati!");          // Time & Sum control
        }
        */
      }
    }
  }
}

void ReadPacket()
{
  /*do	 
  {
    ReadData();
    inBytesArr[i] = word(inByte,inByte2);		// Packet
    i++;
  }
  while(inByte == 0xFF && inByte2 == 0xFF);             // Until footer*/
  while(1)
  {
    ReadData();
    if(inByte != 0xFF && inByte2 != 0xFF)               // Until footer
    {
      inBytesArr[i] = word(inByte,inByte2);		// Packet
      verificaCRC[i] = (char*)inBytesArr[i];
      i++;
    }
    else 
    {
      break;
    } 
  }
}

boolean ControlLenght()
{
  int lung = inBytesArr[0];
  if(lung == i+3)
  {
    return true;
  }
  else
  {
    return false;
  }
}

boolean controlHeader0(int header0, int header1)
{
    if(header0 == 0xFF && header1 == 0xFF)
    {
      return true;
    }
    else return false;
}

boolean controlHeader1(int header, int type)
{
    if(header == 0xFF && type == 0xF2)
    {
      typepacket = 2;
      return true;
    }
    /*...*/  //Possibility To add more types
    else return false;
}

boolean controlCRC()
{
  
  if(crcsum((char*)verificaCRC,inBytesArr[0],polynom) == inBytesArr[13])
  {
    return true;
  }
  else
  {
    return false;
  }
}
/*
boolean controltime(int oldTime, int controlTime)
{
  if(controlTime == 0 && oldTime == 0) return true;        // In the beginning all the time are 0
  if(controlTime == 0 && oldTime != 0) return true;        // When the timestamp reset
  (oldTime < controlTime) ? true : false;                  // If the timestamp I received is less than the timestamp I have there is an error
}
*/

/*
boolean controlSum()
{
  (inBytesArr[15] == (inBytesArr[5] + inBytesArr[6] + inBytesArr[7] + inBytesArr[8] + inBytesArr[9] + inBytesArr[10] + inBytesArr[11] + inBytesArr[12] + inBytesArr[13])) ? true : false;
  //control the sum of the 9 dates with the 15th data
}
*/

void ReadData()
{
  if(Serial2.available() > 1)
  {
    inByte = Serial2.read();                        // Read first 8 bit data
  }
  if(Serial2.available() > 2)
  {
    inByte2 = Serial2.read();	                    // Read second  8 bit data
  }
}

/* CRC16 Definitions */
static const word crc_table[256] = {
  0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
  0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
  0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
  0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
  0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
  0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
  0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
  0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
  0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
  0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
  0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
  0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
  0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
  0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
  0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
  0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
  0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
  0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
  0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
  0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
  0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
  0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
  0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
  0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
  0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
  0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
  0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
  0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
  0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
  0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
  0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
  0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
};

/* CRC calculation macros */

word crcsum(char* message, word length,word crc)
{
  word i;

  for(i = 0; i < length; i++)
    {
      CRC(crc, message[i]);
    }
  return crc;
}
